Unit for Packaging Containers and a Device for Forming Said Containers Produced Continuously from a Tubular Wrapper

ABSTRACT

A device ( 8 ) for forming containers ( 2 ) produced continuously from a tubular wrapper ( 3 ) fed along a substantially vertical direction of advance (A). The device ahs at least one support carriage ( 8   a ) movable along a respective closed pathe (P) having at least one active segment (P′) parallel to the direction of advance (A). The carriage ( 8   a ) supports a sealing base ( 11 ) able to be associated to a first lateral face ( 2   a ) of said tubular wrapper ( 3 ) at a sealing region (Z) of the wrapper ( 3 ) itself. A contrasting element ( 14 ) is removably associated to the support carriage ( 8   a ) and movable between a first closed position in which it is approached to the base ( 11 ) and abuts against a second lateral face ( 2   b ) or the tubular wrapper ( 3 ) opposite to the first latoral face ( 2   a ) at the sealing region (Z), and a second position in which it is movably away from the base ( 11 ). The device also has means ( 10 ) for actuating the support carriage ( 8   a ) able to actuate the carriages ( 8   a ) along the path (P) at variable velocity and means ( 38 ) for cutting said tubular wrapper ( 3 ) to obtain the containers ( 2 ).

TECHNICAL FIELD

The present invention relates to a device for forming containers produced continuously from a tubular wrapper, comprising the characteristics set out in the preamble to claim 1. The present invention further relates to a unit for packaging the aforesaid containers in which the forming device finds advantageous use.

BACKGROUND ART

The invention is in the sector of packaging containers of incoherent material, generally containers of liquids for human consumption. Such containers are produced in continuous fashion from a tubular wrapper fed along a substantially vertical direction. The tubular wrapper is filled with the aforementioned incoherent and subsequently sealed and cut along transversal seal lines which define the individual containers.

As is well known, the wrapper material, generally constituted by heat-sealable paper material, is continuously unwound from a reel towards a folding device adapted to join opposite longitudinal edges of the aforesaid wrapper to each other.

In this way, the tubular wrapper is made to advance along a respective vertical path through a filling unit.

The filling unit delivers inside the tubular wrapper the material to be contained through an upper opening of the tubular wrapper itself.

Downstream of the filling unit develops a forming device provided with heated bards adapted to perform a series of seals, transverse to the longitudinal axis of the tubular wrapper. The heated bars are mounted on a fixed support structure and are movable only to approach each other.

In this way, between a seal line and the other the aforesaid container, previously filled, is defined.

Lastly, a cutting member positioned downstream of the forming device separates the containers from each other by a transverse cut along the seal line.

The known packaging units described above have important drawbacks, linked mainly to the forming device.

It should be noted that the heated bars are positioned at opposite parts of the tubular wrapper and movable to approach each other to press the region to be sealed along a transverse direction to the direction of vertical motion of the tubular wrapper.

Because of the movement of the bars, the tubular wrapper is braked intermittently, causing considerable damage to the seal region. During the motion of the wrapper, the bars slide on the wrapper itself, causing its incorrect seal and the damage of the sealed area.

Moreover, devices able to overcome the aforementioned problems because they are provided with movable bars along the path of the tubular wrapper are known.

As is described for example in European patent EP1125847, the forming device provided with movable bars is constituted by two support frames set site by site to each other and having respective belts, movable along a closed path.

The tubular wrapper is actuated through the belts, at a rectilinear segment of the closed path, parallel to the direction of actuation of the wrapper.

Each belt bears a plurality of carriages which are movable along the path and each carriage in turn bears a heated bar, adapted to abut on the surface to be heated of the tubular wrapper.

In this situation, when the carriages are positioned at the rectilinear segment, the bars of each pair of carriages abut against each other pressing the region to be sealed of the tubular wrapper. The pressing operation is then performed maintaining in motion each pair of carriages along the direction of actuation of the tubular wrapper.

In this solution, although the device described above solves the problem of avoiding any relative sliding between the bars and the wrapper, it has important drawbacks.

Said drawbacks are linked mainly to the structural complexity of the sealing device and of the overall size presented thereby. The containers have a conformation that substantially matches the conformation of the respective tubular wrapper and the pressing of the bars causes a slight deformation of the shape of the container. Consequently, at each seal region of each individual container, the desired shape is not maintained.

DISCLOSURE OF INVENTION

The object of the present invention is to solve the problems noted in the prior art proposing a forming device and a unit for packaging containers, able to solve the aforementioned drawbacks of the prior art.

In detail, the object of the present invention is to provide a device for forming containers that is able to define the shape of the container during the sealing phases.

These objects and others beside, which shall become more readily apparent from the description that follows, are substantially achieved by a device for forming containers, comprising the characteristics set out in the characterizing part of claim 1.

Further characteristics and advantages shall become more readily apparent from the detailed description of a preferred, but not exclusive, embodiment of a forming device and a unit for packaging containers, in accordance with the present invention. Said description shall now be provided below with reference to the accompanying figures, provided purely by way of non limiting indication, in which:

FIG. 1 shows a schematic perspective representation of a unit for packaging containers produced continuously from a tubular wrapper with some parts remove the better to show others;

FIG. 2 is a perspective view of a forming device according to the present invention, schematically shown in FIG. 1;

FIG. 3 is a perspective, schematic view of the device illustrated in FIG. 2 with some parts removed the better to show others;

FIG. 4 is a perspective view of a construction detail of the forming device of FIG. 2;

FIG. 5 is a perspective view of a construction detail of the forming device;

FIG. 6 is a perspective view of an additional construction detail of the forming device;

FIG. 7 is a side elevation view partially sectioned along the trace VII-VII of the forming device shown in FIG. 3;

FIG. 8 is an additional side view partially sectioned along the trace VIII-VIII of the device shown in FIG. 3;

FIG. 9 is a perspective schematic view of the device shown in FIG. 2 with some parts removed the better to show others, in accordance with a second embodiment;

FIG. 10 is a perspective view of a construction detail of the device shown in FIG. 2;

FIGS. 11, 12 and 13 respectively illustrated schematic side elevation views of additional variants of the construction detail of FIG. 10.

DESCRIPTION OF THE ILLUSTRATED EMBODIMENTS

With reference to the accompanying figures, the number 1 globally designates a unit for packaging containers 2 produced continuously from a tubular wrapper 3.

It should be specified that FIG. 1 schematically shows, by way of example, the unit 1 in which some technical details have been removed, the better to clarify the general structure of the unit 1 itself.

In detail, the unit 1 is constituted by means 4 for feeding a continuous strip 3 a of paper material from which the aforesaid tubular wrapper 3 is obtained, as shall be better explained hereafter.

The feeding means 4 are constituted by a reel 5 of the aforesaid continuous strip 3 a and respective transmission rollers 5 a adapted to feed the strip 3 a along a predefined path.

Downstream of the feeding means 4 develops a forming member 6 able to join respective opposite longitudinal edges of the continuous strip 3 a to define the aforementioned tubular wrapper 3. The forming member 6, which is not described and illustrated because it is known, is constituted by a series of sliding guides, respectively twisted to overturn at least one longitudinal edge on the other and mutually seal the aforesaid edges.

The tubular wrapper 3 is then fed along a vertical direction A of the respective path, at a member 7 for filling the wrapper itself.

In greater detail, the tubular wrapper 3 has a respective upper opening corresponding to a portion of the belt 3 a, not yet sealed, in which the incoherent material is dispensed. The filling member 7 is constituted by a dispensing nozzle 7 a positioned at the opening of the tubular wrapper 3 and associated to a respective conduit for containing the incoherent material. For example, if the incoherent material is constituted by a liquid, the nozzle 7 a dispenses the aforesaid liquid inside the tubular wrapper filling it from the respective lower portion to a predetermined height.

Thus filled, the tubular wrapper passes by a forming device 8 which constructs the containers 2 from said tubular wrapper 3.

The forming device 8, illustrated in detail in FIG. 2, is constituted by at least one support carriage 8 a movable along a respective closed path P. The aforesaid path P has substantially elliptical shape and it is constituted by at least one active segment P′ that is parallel and coincident with the vertical direction of advance A of the tubular wrapper 3, and by a passive segment P″ opposite to the active segment P′.

Advantageously, the device 8 has a plurality of carriages 8 a actuated along the path P by respective actuating means 10 as shall be better described below.

In detail, each carriage 8 a is constituted by a pair of shoes 9 associated with a respective sealing base 11 at opposite ends 11 a of the base 11 itself.

As further illustrated in the detail of FIG. 5 and FIG. 6 each shoe 9 has a body 12 having substantially parallelepiped conformation in which is defined an inner surface 12 a engaged to one of the ends 11 a of the base 11 and an outer surface 12 b opposite to the inner surface 12 a.

At the outer surface 12 b of the body 12 are operatively associated a plurality of sliding elements 13, preferably constituted by rotatable casters 13 a.

More in detail, each body 12 has three casters 13 a rotatable about respective axes, transverse to the development of the active segment P′.

At least two of the three casters 13 a are advantageously aligned to each other along the development of the path P, whilst the remaining caster is positioned below the first two.

Each body 12 also has an upper portion 12 c positioned above the base 11 in which is obtained a seat 12 d adapted to house a contrasting element 14.

As mentioned above, between each shoe 9 develops a base 11 having substantially parallelepiped conformation and developing along a respective longitudinal dimension, transverse to the aforementioned active segment P′.

The sealing base 11 is adapted to be associated to a first lateral face 2 a of the tubular wrapper 3, at a seal region Z of the wrapper 3 itself.

It should be noted that the aforementioned seal region Z, which is illustrated more clearly in FIGS. 11 through 13, is constituted by a segment that is transverse to the longitudinal development of the tubular wrapper 3 whereat is joined a respective first lateral face 2 a of the wrapper 3 itself with a second lateral face 2 b opposite to the first one. In this way, between two seal regions Z is defined each individual container 2.

The sealing base 11 has a first surface 15 able to be associated to the first lateral face 2 a of the wrapper 3 and having longitudinal development corresponding to the seal region Z.

Preferably, the first surface 15 has respective sealing means, known in themselves and therefore not further described in detail. For example, said sealing means can be constituted by an electrically heated lamina, a radio frequency emitter, or an ultrasound emitter.

As is better illustrated in FIG. 4, each sealing base 11 also has a second surface 16 opposite and parallel to the first surface 15. From the second surface 16 develop a first and a second projecting element 17, 18 respectively side by side to each other. The first projecting element 17 has an insertion pivot 17 a which extends transversely to the planar surface of the second surface 16 below the base 11. The second projecting element 18 has an opening 18 a obtained on the element 18 and oriented below the base 11.

As previously mentioned, each body 12 of the respective shoes 9 has an upper portion 12 c in which is obtained the seat 12 d able to house the contrasting element 14.

In this situation each shoe 9 has a contrasting element 14 movable between a first closed position in which it is approached to the base 11 and it abuts on the second lateral face 2 b of the tubular wrapper 3 at the seal region Z, and a second position in which it is moved away from the base 11.

In detail, each carriage 8 a has two contrasting elements 14 associated at respective opposite ends 15 a of the first surface 15 and each of which develops from the respective end 15 a to a median portion of the first surface 15. In this situation, the contrasting elements 14 of each carriage 8 a are movable symmetrically between the first position in which they are side by die along a same longitudinal axis (see for example FIGS. 4 and 5) and the second position in which they face each other and are transverse to the longitudinal development of the first surface 15 (see for example FIG. 3).

In yet more detail, each contrasting element 14 is constituted by a bar 19 having a respective active surface 19 a able to abut on the first surface 15 of the base 11 in the first position of the contrasting element 14 itself.

Advantageously, also the active surface 19 a of the bar 19 can have known sealing means, previously described in exemplifying fashion.

In this situation, the pressure exerted by the active surface 19 a of the bar 19 and of the first surface 15 of the base 11 determines the pressing of the region Z of the tubular wrapper and the consequent sealing thereof.

Each bar 19 also has an end portion 20 positioned at an end 11 a of the base 11.

In particular, the end portion 20 is inserted rotatably in the seat 12 d obtained in the upper portion 12 c of the respective body 12.

In still further detail, the end portion 20 is inserted in the upper portion 12 c by means of a through pivot 20 a, in such a way as to make the bar 19 rotatable about an axis that is perpendicular to the planar development of the first surface 15 of the base 11.

Additionally, at each end portion 20 of the respective bar 19, develops a sliding element 13 positioned above the bar 19. This sliding element, too, is constituted by a caster 13 a rotatable about a respective axis, transverse to the longitudinal development of the respective bar 19.

The means 10 for actuating the carriages 8 a have at least one support guide 22 to guide the aforesaid carriages 8 a along the closed path P.

Advantageously, as shown in the accompanying figures, two support guides 22 are provided, parallel and distanced from each other, each of which is associated to each shoe 9 of each carriage 8 a.

In greater detail, each guide 22 is constituted by a rail 22 a developing along a substantially elliptical path, corresponding to the development of the closed path P.

In this situation, the casters 13 a of each body 12 rotated on the respective rail 22 a, in such a way as to slide along the aforesaid path P.

As shown in detail in FIG. 5, each rail 22 a is interposed between the sliding elements 13 in such a way that for each body 12 of the shoe 9 are positioned two casters 13 a aligned to each other on an upper surface 22 b of the rail 22 a itself, and a third caster 13 a on a lower surface 22 c of the rail 22 a.

With reference to FIG. 3, it should be noted that each rail 22 a is constituted by a primary rectilinear portion 23 parallel to the direction of advance A of the tubular wrapper and corresponding to the aforesaid active segment P′ of the closed path P. The rectilinear portion 23 has an entrance region 23 a of the wrapper 3 and an exit region 23 b of the wrapper.

Moreover, each rail 22 a has a secondary rectilinear portion 24 opposite and parallel to the primary rectilinear portion 23 and two arched junction portions 25 between the primary 23 and secondary 24 rectilinear portions.

In this situation, the secondary rectilinear portion 24 and the arched portions 25 constitute the aforesaid passive segment P″ of the closed path P.

Each guide 22 also has a side panel 26 positioned at the primary rectilinear path 23 and able to be associated to the bar 19 to actuate the contrasting elements 14 between the respective first and second position.

In detail, the side panels 26, each of which is associated to a respective guide 22, are constituted by a contrasting surface 27, twisted and facing the carriages 8 a. In yet closer detail, as better shown in FIG. 4, each contrasting surface 27 has a first portion 27 a parallel to the planar development of the first surface 15 of the base 11, and a second portion 27 b consecutive to the first portion 27 and transverse to the planar development of the aforesaid first surface 15.

In this situation, each caster 13 a associated to the respective end portion 20 of the corresponding bar 19 rotates on the contrasting surface 27 to rotate the bar 19 between the respective first and second position.

Advantageously, when each caster 13 a associated to the respective bar 19 rotates on the first portion 27 a of the contrasting surface 27, the corresponding contrasting element 14 is in the respective second position in which it is detached from the respective base 11. During the advance of the carriage 8 a the caster 13 a associated to the respective bar slides on the twisted portion rotating the contrasting element 14 about the pivot 20 a, until the caster 13 a is able to slide on the second portion 27 b of the contrasting surface 27 b, and the corresponding contrasting element 14 is positioned in the respective second position in which it is approached to the base 11.

The actuating means 10 also have a first motor member 28 to actuate the carriages 8 a along the active segment P′ of the path P and a second motor member 29 to actuate the carriages 8 a along the passive segment P″ opposite to the aforesaid active segment P′.

As shown in FIG. 7, the first motor member 28 has a transport element 30 whose longitudinal development is parallel to the aforesaid active segment P′ and associated to a motor 31. Both the motor 31 and the transport element 30 are interposed between the guides 22.

Preferably, the transport element 30 is constituted by an auger 32 rotatable about a respective longitudinal axis parallel to the aforesaid active segment P′.

More in particular, the auger 32 is constituted by a cylindrical body having an outer surface in which is obtained a helical cavity 32 a. In this situation, when a carriage is positioned in the active segment P′ the insertion pivot 17 a of the first projecting element 17 of the respective base 11 is inserted in the helical cavity 32 a.

Advantageously, as a result of the rotation of the auger 32, the pivot 17 a slides along the helical cavity 32 a driving the base 11 and the respective pair of shoes 9 along the active segment P′ corresponding to the longitudinal development of the auger 32.

The auger 32 is set in rotation by means of the motor 31 through appropriate motion transmission members 31 a, known and therefore not further described in detail. For example, said transmission members 31 can be constituted by a pair of pulleys associated respectively to the drive shaft and to an end of the auger and associated to each other by means of a belt. It should be specified that the auger 32 has a helical cavity 32 a with variable pitch, in order to vary the velocity of each carriage 8 a in the active segment P′.

In this situation, the helical cavity 32 a has a first portion placed at the entrance region of the primary rectilinear portion 23 and a second portion, contiguous to the first portion and positioned at the exit region 23 b. The first portion has a greater pitch (distance between a point of the cavity and the successive symmetrical point) than the pitch of the second portion.

In this way, when the carriage 8 a slides along the greater pitch of the cavity 32 a, it increases its speed because of the greater distance of the pitch without varying the angular velocity of the auger 32.

In an additional embodiment variant shown in FIG. 9, the first motor member 28 is constituted by a first and a second transport element 30 and 30′ side by side to each other. In particular, the two transport elements 30 and 30′ are respectively constituted by a first and a second auger 32 and 32′ having longitudinal development, mutually parallel and parallel to the aforesaid active segment P′. The first and the second auger 32 and 32′ have respectively the helical cavities 32 a and 32 a′ with mutually different pitch, i.e. one of the cavities has a greater distance between one point and its next symmetrical point that the other helical cavity.

In this situation, the bases 11 belonging to respective carriages 8 a have the first projecting element 17 positioned at the first or at the second auger 32 and 32′.

In this way, the base 11 of a carriage 8 a has the respective pivot 17 a associated to the helical cavity 32 a of the first auger 32 and the subsequent carriage 8 a has the respective pivot 17 a associated to the helical cavity 32 a′ of the second auger 32′.

In this way, every carriage 8 a can be actuated along the active segment P′ at a different speed from the subsequent and from the previous carriage 8 a.

Alternatively, a first and a second auger 32 and 32′ can be provided, with respective helical cavities having the same pitch. In this situation, the two augers are actuated independently of each other and with different velocity to differentiate the velocity of advance of each carriage 8 a.

With reference to FIG. 8, the second motor member 29 has at least two pulleys 33 positioned mutually side by side, each of which is positioned at an arched portion of junction 25. The pulleys 33 rotate about respective axes, mutually parallel and parallel to the planar development of the first surface 15 of each base 11.

The pulleys 33 are respectively associated to a belt 34 positioned substantially along the aforesaid passive segment P″ to transport each carriage 8 a along the segment P″ itself.

The second motor member 29 also has at least one transmission roller 35 of the belt 34 positioned between two pulleys 33 to distance the belt 34 from the first motor member 28.

In detail, the belt 34 has an inner surface 34 a able to abut against the pulleys 33 and an outer surface 34 b opposite to the inner surface 34 a oriented towards the guides 22 and associated to the transmission roller 35. In this situation, as shown in FIG. 8, the belt 34 slides along a substantially two-lobed closed path defining the passive segment P″.

Additionally, the belt 34 has a plurality of engagement pivots 36, mutually equidistant and extending from the outer surface 34 b of the belt 34 (also visible in FIG. 4).

In this situation, the transmission roller 35 which can abut against the outer surface 34 b of the belt 34, has respective seats able to receive the engagement pivots 36 during the actuation of the belt 34.

The engagement pivots 36 are advantageously shaped complementarily to the openings 18 a obtained in the respective second projecting elements 18 of the bases 11 and able to be inserted into the openings 18 a.

In detail, when one of the carriages 8 a is positioned at the passive segment P″ and then placed at the aforesaid belt 34, an engagement pivot 36 is inserted into the respective opening 18 a and drives, by the motion of the belt 34, the respective carriage 8 a along the passive segment P″.

Advantageously, as shown in FIGS. 2, 5 and 7, the device 8 also has a plurality of walls 37 each of which is associated between two successive shoes 9 and adapted to be able to abut to a flank 2 c of the tubular wrapper 3 transverse to the aforesaid first and second lateral face 2 a, 2 b.

In particular, the walls 37 have substantially plate-like development and their planar development is transverse to the planar development of the first surface 15 of each base 11.

Preferably, a pair of walls 37 are provided, respectively associated between each carriage 8 a and the adjacent carriage 8 a.

As shown in FIG. 7, each wall 37 has a first end 37 a pivotally engaged to a corresponding shoe 9 at the second surface 16 of the base 11, and a second end 37 b opposite to the first. The second end 37 b has a pivot, slidable within a slot whose development is parallel to the closed path P and which is obtained in a projection of the respective shoe 9. In this way, the adjacent carriages 8 a can approach or move away from each other making the aforesaid pivot in the aforementioned slot.

Each pair of walls 37 then abuts respective opposite flanks 2 c of the tubular wrapper to give a substantially parallelepiped shape to each individual container 2 during the sealing of the region Z. Moreover, by virtue of the fact that the walls 37 are associated to the shoes 9, it should be noted that the walls 37 themselves are positioned abutting the opposite flanks 2 c of the wrapper 3 only when the shoes are positioned along the active path P′.

The forming device 8, lastly, has means 38 for cutting the tubular wrapper 3, which are operatively active at the seal region Z to obtain the individual containers.

The cutting means 38 have at least one separator device 39 illustrated in detail in FIG. 10 and positioned downstream of the active segment P′ relative to the direction of advance A of the tubular package 3.

The separator device 39 is constituted by a support frame 40 secured to a load-bearing structure 41 of the forming device 8 (see FIG. 2). The support frame 40 is constituted by an upright 40 a developing above the tubular wrapper 3 transversely to the direction of advance A of the tubular wrapper 3.

On the upright 40 a is secured a motor 42, known and therefore not described further in detail, operatively associated to an arm 43, movable transversely to the direction of advance A between a first position in which it is moved away from the tubular wrapper 3 and a second position in which it is approached to the seal region Z of the wrapper 3 itself.

In particular, the arm 43 has substantially longiform conformation in which a first end 43 a is defined, positioned at the motor 42 and associated thereto by means of a transmission member 44. The transmission member 44 is constituted by a connecting rod-crank kinematic mechanism with three pulleys 44 a set in rotation by the motor 42 by means of a belt 44 b.

The first end 43 a is pivotally engaged to two of the three pulleys 44 a (see FIG. 10) at an off-centre point of the pulleys.

In this way, the rotation of the pulleys 44 a determines the rectilinear reciprocating movement of the entire arm 43 between the respective aforementioned first and second position.

The arm 43 also has a second end 43 b opposite to the first end 43 a in which is obtained a housing seat of a blade 45 whose longitudinal development is parallel to the longitudinal development of the first surface 15 of each base 11.

Advantageously, when the arm 43 is in the corresponding second position, the blade 45 is positioned above the seal region Z in order to cut it longitudinally. In this situation, after the transverse cut of the wrapper 3 the blade 45 abuts against the first surface 15 of the base 11 positioned below the blade 45 itself. It should be noted that, when the blade 45 approaches the wrapper 3 to cut the seal region Z, the contrasting elements 14 positioned on the respective base 11 are moved away from the first surface 15. In this way, the arm 43 can freely approach the tubular wrapper 3 without being hindered by the contrasting elements 14.

In accordance with an alternative embodiment shown in FIG. 11, the separator device 38 is positioned downstream of the guides 22 along the direction of advance A. In this solution, two arms 43 and 43′ are provided, facing each other and with each of them having the respective blade 45, 45′.

Still with reference to FIG. 11, it should be noted that the tubular wrapper 3 is positioned between the two arms 43, 43′ which are actuated in mutually independent fashion to move closer or farther away from each other.

Advantageously, when the arms 43, 43′ are movable to approach each other, the respective blades 45 and 45′ abut against each other in such a way as to cut the tubular wrapper 3 transversely at the respective seal region Z.

In the embodiment variant of FIG. 12, the second end 43 b′ of the arm 43′ has a contrasting support 46, adapted to abut against the blade 45 of the other arm 43.

In this solution, the contrasting support constitutes a fixed support of the blade 45 and it is advantageously provided with a recess (not shown in the figure) inside which is housed the blade 45.

FIG. 13 shows an additional embodiment variant of the separator device 38. In this solution, only one arm 43 as described above is present and it is positioned at the active segment P′ above the side panels 26.

Additionally, in accordance with this alternative solution, the bars 19 of the contrasting elements 14 have a through opening 47 which extends longitudinally along each bar 19. When the bars 19 are both approached to the first surface 15 of the respective base 11, the through openings 47 of the bars 19 are mutually side by side and aligned in such a way as to define a single opening whose longitudinal development matches the longitudinal development of the seal region Z.

The respective base 11 has a recess 48 obtained on the first surface 15 and developing along the longitudinal development of the surface 15. Advantageously, as is readily apparent in FIG. 13, the recess 48 is placed at the openings 47 of the bars 19 when the bars 19 abut against the region Z to be sealed.

In this situation, when the contrasting elements 47 abut against the region to be sealed Z, the blade 45 can be inserted into the openings 47 of the bar 19.

In this way, the blade 45 passes through the openings 47 and cuts the region Z longitudinally until it inserts itself into the recess 48.

The operation of the packaging unit 1 and of the respective forming device 8, described above in prevalently structural sense, is as follows.

With reference to FIG. 1, the continuous strip 3 a is fed from the respective reel 5 towards the forming member 6 of the tubular wrapper 3. The forming organ 6 folds at least one longitudinal edge of the continuous strip 3 a on the other and longitudinally seals the region of superposition of the edges.

In this way, the tubular wrapper 3 is defined and fed along the vertical direction A by appropriate members, not described or illustrated in detail above because they are known.

The tubular wrapper 3 fed vertically has a respective upper opening defined by the respective longitudinal edges, not yet sealed. Advantageously, the filling member 7 delivers the incoherent material inside the tubular wrapper 3 through the aforementioned upper opening. In this situation, the tubular wrapper 3 positioned vertically is filled only up to a certain height.

The tubular wrapper 3 thus filled passes at the forming device 8 along the active segment P′ of the closed path P.

Starting from a carriage 8 a which passes from the passive segment P″ to the active segment P′, it should be noted that the first surface 15 of the base 11 abuts against the first lateral face 2 a of the wrapper 3. In this situation, the respective pivot 17 a is positioned in the helical cavity 32 a and by means of the rotation of the auger 32 the pivot slides along the cavity 32 a driving the respective base 11 and the shoes 9 along the active segment P′.

The sliding elements 13 of the respective shoes 9 slide along the primary rectilinear portions 23 of the respective guides 22 at the same velocity of advance as the tubular wrapper 3.

When the shoes 9 are at the side panels 26, the respective contrasting elements 14 are positioned in the corresponding first closure position.

In particular, when the carriage 8 a arrives at the side panels 26, each sliding element 13 positioned on the respective bar 19 slides on the first portion 27 a of the contrasting surface and subsequently, following the twisted profile of the contrasting surface 27, it advances until reaching the second portion 27 b. In this way, the sliding elements 13 positioned on the bars 19 move from a position in which they rotate on the first portion 27 a about an axis that is parallel to the planar development of the first surface 15 of the base, to a position in which they rotate on the second portion 27 b about an axis that is perpendicular to the planar development of the first surface 15.

Consequently, the bars 19 that are associated to the respective sliding elements 13 rotate about the through pivot 20 a positioning themselves above the second lateral face 2 b to press the lateral face 2 b itself.

Because of the pressing of the bars 19 against the base 11, the lateral faces of the wrapper 3 are sealed and the sealing region Z obtained during the continuous advance of the wrapper 3 itself along the direction A.

When the carriage 8 a advances outside the side panels 26, the contrasting elements return to the corresponding second position in which the bars 19 are moved away from the base 11. Advantageously, moreover, a spring 50 (shown in FIG. 4) can be provided, positioned about the pivot 20 a, which spring 50 determines the return of the contrasting element 14 in the respective second position.

It should be noted that advantageously, multiple carriages 8 a are positioned simultaneously on the active segment P′ in such a way that at least two successive carriages 8 a are at the side panels 26. In this situation, the tubular wrapper 2 can be sealed simultaneously in multiple parts or individually at different times.

Advantageously, because of the variation in the pitch of the auger, successive carriages 8 a move faster in the initial segment P′.

In this way, a displacement of the respective seal regions Z which are mutually approached.

Advantageously, because of this longitudinal squashing of the tubular wrapper 3 the individual containers 2 are deformed to give them a specific shape.

For example, during the longitudinal squashing of the wrapper 3, the flanks 2 c of the wrapper 3 itself are deformed towards the exterior in such a way as to adhere to the walls 37. In this situation, the containers 2 are formed with parallelepiped shape in which the flanks 2 c constituted opposite lateral walls.

In the embodiment of FIG. 9, each carriage 8 a is associated in alternating fashion to one of the two augers 32, 32′.

When the contrasting elements 14 return to the respective second position, the carriage 8 a is positioned at the separator device 38. At this point the arm 43 is actuated towards the base 11 until the respective blade 45 abuts on the seal region Z to cut it. As a result of the transverse cut of the tubular wrapper 3, the blade 45 bears on the first surface 15 of the base 11 and subsequently the arm 43 is moved away from the base 11.

Advantageously, the containers 2 previously filled and formed are obtained as a result of the transverse cut.

In the embodiments illustrated in FIGS. 11 and 12, the tubular wrapper 3 is made to advance sealed outside the guides 22 to allow the two arms 43 to approach each other and to cut the wrapper along the region Z to define the containers 2.

In accordance with the embodiment of FIG. 13, the separator device 13 is positioned above the side panels 26 and the arm 43 approaches the wrapper 3 when the contrasting elements 14 are still pressing and sealing the wrapper 3.

In this situation, the blade 45 passes through the openings 47 obtained on the bars 19 to cut the region Z whilst it is sealed. Advantageously, at the end of the sealing operation, i.e. when the contrasting elements 14 move away from the tubular wrapper 3, the container 2 is already detached from the remained of the wrapper 3.

Once the transverse seal is completed, the carriage 8 a passes from the active segment P′ to the passive segment P″. In this situation, the pivot 17 a reaches the end of its travel in the helical cavity 32 a and the base 11 is positioned at one of the two pulleys 33.

One of the engagement pivots 36 positioned on the belt 34 is then inserted into the opening 18 a driving the carriage 8 a along the passive segment P″ in the two arched portions 25 and in the secondary rectilinear portion to return the pair 9 to the active segment P′.

The present invention solves the problems noted in the prior art and achieves the proposed objects.

By means of the longitudinal approach between two continuous carriages 8 a, the containers 2 can be formed while they are formed.

It should be noted that, during the longitudinal displacement of the carriages 8 a the seal regions Z of each individual container 2 are mutually approached and squashed, approaching said regions to the body of the container 2. Consequently, the lateral surfaces of the container 2 abut against the walls 37 which also give shape to the lateral surfaces. 

1. A device for forming containers (2) produced continuously from a tubular wrapper (3) fed along a substantially vertical direction of advance (A), characterised in that it comprises: a plurality of support carriages (8 a) movable along a respective closed path (P) having at least one active segment (P′) parallel to-said direction of advance (A); each support carriage (8 a) having a sealing base (11) able to be associated to a first lateral face (2 a) of said tubular wrapper (3) and a contrasting element (14) movable between a first closed position in which it is approached to said base (11) and engaged to a second lateral face (2 b) of the tubular wrapper (3) opposite to the first lateral face (2 a), and a second position in which it is movable away from said base (11); means (10) for actuating said plurality of support carriages (8 a) along the path (P) to move each carriage at a variable velocity along the active segment (P′); and means (38) for cutting said tubular wrapper (3) operatively active at said seal region (Z) to obtain said containers (2).
 2. Device as claimed in claim 1, characterised in that each support carriage (8 a) is progressively slowed along said active segment (P′).
 3. Device as claimed in claim 1 or 2, characterised in that said means (10) for actuating said support carriages (8 a) comprise: at least one supporting guide (22) to guide the support carriages (8 a) along said closed path (P); a first motor member (28) to actuate the support carriages (8 a) along the active segment (P′); and a second motor member (29) to actuate the support carriages (8 a) along a passive segment (P″) opposite to said active segment (P′).
 4. Device as claimed in claim 3, characterised in that said first motor member (28) comprises a transport element (30) extending parallel to said active segment (P′); and a motor (31) associated to said transport element (30).
 5. Device as claimed in claim 4, characterised in that said transport element (30) has an auger (32) able to rotate about a respective longitudinal axis corresponding to said active segment (P′); said insertion pivot (17 a) extending from each base (11) being able to be inserted into a helical cavity (32 a) obtained on the outer surface of said auger (32) to move the respective carriage (8 a) along the primary rectilinear portion (23).
 6. Device as claimed in claim 5, characterised in that said helical cavity (32 a) of the auger (32) has a variable pitch.
 7. Device as claimed in claim 6, characterised in that said helical cavity (32 a) has a first portion and a second portion, contiguous to the first portion; said first portion of the helical cavity (32 a) having greater pitch than the second portion.
 8. Device as claimed in claim 7, characterised in that at least two carriages (8 a) are simultaneously associated to the auger (32), each of which having the respective insertion pivot (17 a) associated to the helical cavity (32 a) respectively at the first and second portion.
 9. Device as claimed in claim 4, characterised in that said transport element (30) has a first and a second auger (32, 32′) side by side to each other and each of which is rotatable about a respective longitudinal axis corresponding to said active segment (P′).
 10. Device as claimed in claim 9, characterised in that said insertion pivot (17 a) of each base (11) can be inserted into a helical cavity (32 a, 32 a′), obtained on the outer surface of one of said first or second auger (32, 32′) to move the respective carriage (8 a) along the primary rectilinear portion (23).
 11. Device as claimed in claim 10, characterised in that at least one carriage (8 a) is associated to the first auger (32) and the subsequent and preceding carriage are associated to the second auger (32′).
 12. Device as claimed in claim 10, characterised in that the helical cavity (32 a) of the first auger (32) has a greater pitch than the pitch of the helical cavity (32 a′) of the second auger (32′).
 13. Device as claimed in claim 10, characterised in that the helical cavity (32 a) of the first auger (32) has a smaller pitch than the pitch of the helical cavity (32 a′) of the second auger (32′).
 14. Device as claimed in claim 10, characterised in that the helical cavity (32 a) of the first auger (32) and the helical cavity (32 a′) of the second auger have equal pitch; each auger (32, 32′) being actuated independently and at different velocities.
 15. Device as claimed in claim 3, characterised in that said actuating means (10) comprise two support guides (22), mutually parallel and distanced from each other, each of which is associated to a respective shoe (9) of each support carriage (8 a).
 16. Device as claimed in claim 15, characterised in that each guide (22) has a rail (22 a) having elliptical development and matching the development of said closed path (P).
 17. Device as claimed in claim 16, characterised in that each rail (22 a) has: a primary rectilinear portion (23) parallel to said direction of advance (A) of the tubular wrapper (3) and corresponding to said active segment (P′) of the closed path (P) said primary rectilinear portion (23) having a region (23 a) for the entrance of the tubular wrapper (3) and a region (23 b) for the exit of the wrapper (3); a secondary rectilinear portion (24) opposite and parallel to said primary rectilinear portion (23); two arched junction portions (25) between said primary rectilinear segment (23) and secondary rectilinear segment (24), opposite to each other; said secondary rectilinear portion (24) and arched portions (25) corresponding to said passive segment (P″) of the closed path (P).
 18. Device as claimed in claim 1, characterised in that it further comprises a plurality of walls (37) each associated to each carriage (8 a) and to the respective subsequent carriage (8 a), said wall (37) being able to abut against a respective flank (2 c) of the tubular wrapper (3) transverse to the first and second lateral face (2 a, 2 b).
 19. Device as claimed in claim 18, characterised in that it comprises a plurality of pairs of wails (37), each pair being associated respectively to one of said support carriages (8 a) and to the respective subsequent support carriage (8 a) and being able to abut against respective opposite flanks (2 c) of the tubular wrapper (3).
 20. A unit for packaging containers (2) comprising: means (4) for feeding a continuous strip of paper material (3 a); a forming member (6) to join opposite longitudinal elements of said continuous strip (3 a) and to form said tubular wrapper (3); and a filling member (7) positioned downstream of said forming member (6) to fill the tubular wrapper (3) with an incoherent material; characterised in that it comprises a device (8) for forming containers (2) produced continuously from the tubular wrapper (3) in accordance with claim
 1. 21. Device as claimed in claim 11, characterised in that the helical cavity (32 a) of the first auger (32) has a greater pitch than the pitch of the helical cavity (32 a′) of the second auger (32′).
 22. Device as claimed in claim 13, characterised in that the helical cavity (32 a) of the first auger (32) has a smaller pitch than the pitch of the helical cavity (32 a′) of the second auger (32′).
 23. Device as claimed in claim 14, characterised in that the helical cavity (32 a) of the first auger (32) and the helical cavity (32 a′) of the second auger have equal pitch; each auger (32, 32′) being actuated independently and at different velocities. 